Implement roles in Nextcloud

Is your feature request related to a problem? Please describe.
The main problem is that, in medium and large scale, we have to define permissions for a category of users, which are spread into multiple organizational groups, and a same group contains different categories of users which need different features/permissions.
The feature of "Groups" in Nextcloud can be used as both an organizational container of users, e.g. seperating different branches of a company, and a permission container, configured in group whitelists/blacklist in Apps or Admin panel.
Therefore, we have to assign users to at least two groups, one for organizational struture and one for feature permission.
As an undesired result, all those groups are visible and configurable in different and inconsistant places in the interface such as Share list, Talk app, Personal settings, Apps panel, Group folders... which is confusing for both users and admins.
The concept of "Roles" takes on its full meaning here,

Describe the solution you'd like
Please implement the concept of "Roles" in Nextcloud to separate organizational struture and user permissions.
Permissions should be configurable in one unique and centralized place related to roles.
Moreover, the user should not be aware of the role he belongs to, this is a technical information only handled by admins.

Describe alternatives you've considered
When I have to restrict feature access to some users, I have to create a group, assign users to it, update authorized group whitelist in different places in Apps panel and/or in Admin panel (e.g. Talk app, Group Folder).
This is really not convenient.

The issue names no files, tests, or entry points. Start by reviewing the existing group whitelists and blacklists in the Apps and Admin panels, then map how roles would centralize permissions while hiding role membership from users; done means a defined, consistent role-based permission model across the listed interfaces.